I am characterizing the Estrogen Binding Protein (EBP1) isolated from the pathogenic fungus C. albicans, in order to identify the physiological role of this enzyme. Various lines of evidence suggest a relationship between estrogens and the pathogenicity of this organism, and this protein represents the only estrogen binding activity identified in C. albicans. Therefore, we are pursuing the characterization of this protein with the goal of isolating its small molecule substrates. Recent work has demonstrated that EBP1 is homologous to an enzyme found in plants involved in a lipid signaling pathway, and we are interested in determining whether or not EBP1 has a similar function in C. albicans. Our approach in solving this problem has been to study the structure of a highly conserved homolog using the Computer Graphics Lab resources in order to identify and generate active site mutants that are fully competent in substrate binding, but catalytically compromised. One such mutant has been made, and I have shown that this mutant is hampered in its ability to turnover substrate while retaining its ability to bind that substrate. I am currently exploring the use of this mutant in isolating the physiological substrate. The use of the Computer Graphics laboratory has been critical in interpreting the data I've obtained in the lab. It is possible that this research will enable us to describe an as yet unknown lipid signaling pathway in this fungus, and further understand how the pathogen interacts with its human host.